Mankind has known of cribs and cradles for infants and children for many centuries. Initially they undoubtedly were hammock-like members swingably supported. For centuries they were not more than a frame connected to a pair of end pieces having rounded bottom surfaces such that the frame would rock upon being moved sideways.
In more modern times, the frame was rockably mounted upon a relative stationary support, slatted sides being provided whereby the child could stand up in the bed, thus advancing the age of children who could use the combination of a cradle and bed. Age old problems remained, however, such as: structural stability and serviceability, gentleness of rocking and the quietness of rocking of the children's bed.